L-色氨酸发酵过程偶联膜分离提取工艺研究

摘要

Objective:To couple the fermentation process with the membrane separation and extraction process,so as to prolong the the whole L-tryptophan production period and reduce the accumulation of acetic acid and increase the production of target product and reduce the accumulation of the repressor.Methods:The membrane separation and extraction process was started when the amount of acetic acid reached 5 g/L and the fermentation time lastet for 21 h.The fermentation was continued when the dialysis medium was added.Results:With the application of membrane coupled fermentation technology,the biomass increased by 3.4％,and the accumulation of glutamic acid decreased by 54.34％,and the accumulation of acetic acid decreased by 55.36％.The whole acid production period extended 12 h,and the glucose conversion rate improved 6.9％.Conclusion:The application of membrane coupled fermentation technology can significantly increase the production of tryptophan and reduced the accumulation of the repressor.The whole L-tryptophan production period was prolongated,and the glucose conversion rate has improved.%目的:将发酵过程与膜分离提取过程相偶联,解决现有产酸周期短、乙酸积累较为严重等问题,以提高目的产物的产量,降低代谢抑制物质的积累量.方法:将发酵罐与陶瓷膜分离装置相偶联,在发酵时长21 h、乙酸积累量达到5 g/L时开始膜过滤浓缩菌液,结束后补加透析培养基继续发酵.结果:采用膜偶联发酵技术,与传统发酵工艺相比,菌体生物量提高3.4％,谷氨酸积累量下降54.34％,乙酸积累量下降55.36％.整个发酵过程产酸周期延长了12 h,发酵过程中糖酸转化率提高6.9％.结论:采用膜偶联发酵技术发酵生产色氨酸,可以显著提高色氨酸产量,降低代谢副产物的积累量,延长产酸周期,提高糖酸转化率.